Within this article on Phlox douglasii is a key to the cushion-forming Phlox spp. of Oregon:
Interesting article. I guess I never really thought about the ancestry of the P. douglasii hybrids before.
The key is nice to have, I find the western Phlox a hard bunch to differentiate.
From the High Desert Steppe
of the Great Basin and the Eastern
Escarpment of the Sierra Nevada Range
Located in Reno/Sparks,NV zone 6-7
John P Weiser